Air-compressor.



PATENTED AUG. 14; 1906.

T. H, SMITH.

AIR COMPRESSOR.

'APPLIOATION FILED MAY 27, 1905.

2 SHEETS-SHEET 1.

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PATBNTED 'AUG. '14, 1906.

' T. H. SMITH.

AIR. COMPRESSOR.

APPLICATION FILED mum, 1905.

2 SHBETSSHEET Z.

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UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Aug. 14, 1906:

. Application filed m 27,1905. Serial No. 262,623.

To all whom it may concern.-

Be it known that I, THEODORE E. SMITH, a citizen of the United States of America, residing at San Francisco, county of San Francisco, and State of California, have invented certain new and useful Improvements in Air- Compressors; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to an improvement in the manner of operating the eductionvalves of air-compressing engines, as hereinafter described, and illustrated by drawings that form a part of this specification.

My improvement consists in an actuatingpiston operated by air-pressure that automatically opens and closes the eduction passa e or passages from the air-compressing cy inder and in devices to this end.

The object of my invention is to secure an easy, prompt, and noiseless movement of valves of air-compressing engines contingent on pressure within the compressing-cylinder, the reduction of clearance-space, endurance of wear, and simplicity of parts.

To these ends I employ devices as illustrated in the drawings.

Figure I is an end view of an air-compressing engine fitted with my improvements. Fig. II is a plan view of the device shown in Fig. I, the valve-moving piston being in section, the induction-valve being omitted. Fig. III is a partial longitudinal section through the air-compressing cylinder and in duction-valve, showing also the end of the eduction-valve-moving piston-rod, the view being taken to correspond with Fig. I and at an angle of forty-five degrees from Fig. II.

Fig. IV is an enlarged front view of the educ tion-valve and its accessories with a portion of the cylinder-cover, the valve-actuating piston being on the right instead of on the left, as in Fig. I. Fi V is a central longitudinal section throug the device shown in Fig. IV.

The construction of sliding valves lends itself particularly to the narrow plane available for valve-space at the ends of air-com pressing engines, where clearance causes more or'less loss in any case. It also enables balancing by counter-pressure and has other advantages.

Referring to the drawings, 1 is a broken section of the cylinder of an air-compressing engine, 2 the piston thereof, and 3 the back cylinder-cover, which is the same as at the other end of the cylinder except as to a packing-gland for the piston-rod 4.

5 is the induction slide-valve of the gridiron type operated by a stem 7 and lever 8 or other suitable mechanism that will raise this valve and open the ports 9 when the piston begins to move back from the head 3 and causes a partial vacuum in the chamber 10. 12 is the eduction-valve to which my invention especially relates. This valve is also of the sliding gridiron type, having three ports 13 of unequal length to bring them all within the balancing-ring 24 and chamber 14 opposite to the end of the discharge-pipe 15. These packing or balancing rings 24, contrary to the usual construction, are subject to pressure inside and bear against the cover 26 of the chamber 17, forming a seal over the end of the pipe 15 and dispensing with a packinggland on the stem 20. The balancing-ring moves with the valve. This education-valve 12 is moved by a piston 18 in the short cylinder 19, a stem 20 connecting to the valve 12, as shown in the drawings. This piston 18 is moved forward, and the valve is opened by air admitted through a small port 22, that communicates directly with the chamber 10 or interior of the cylinder 1, as indicated in Figs. I and II and shown in Fig. V, and is moved in the other direction by static pressure of the air already compressed passing through the pipe 23 from the discharge-pipe 15; also in part by suction in the chamber 10; This valve 12 remains normally closed by reason of the air-pressure in the pipes 15 and 23 until the advancing piston 2 compresses the air in the cylinder 1 and chamber 10 to a pressure greater than that in the pipe 15. Then the piston 18 will move back and open the valve 12, permitting the compressed air to flow into the pi e 15. The piston 18, be-

ing operated by t e difference between the of valves for an air-compressing engine is ap- 1o 5 plicable alike to each end thereof or to double-acting machines. It will also be understood that any of the parts can be made cellular and cooled by circulating water.

Having thus described the nature and ob- 11o jects of my invention, what I claim as new,

and desire to secure by Letters Patent, is

1. In an air-compressing engine, a sliding eduction-valve of the gridlron type, a pneumatic piston to move said valve, a chamber and balancing-ring at the rear of the valve and moving therewith, and an air-discharge pipe with which said chamber communicates, substantially as specified.

2. In an air-compressing engine, a compressing-cylinder, a sliding eduction-valve of the gridiron type, a piston to move the same, said piston communicating with the air-compressing cylinder, whereby it is operated in one direction, and with the air-discharge pipe, whereby it is operated in the other direction, a chamber at the rear of said valve, a balancing-ring in said chamber, sealing against escape of air outwardly from the valve and moving therewith, and an air-discharge pipe at the rear of said chamber, com- Inunicating with the same, substantially as specified.

8. In an air-compressing engine, a compressing-cylinder, an air-discharge pipe, a sliding eduction-valve of the gridiron type, a pneumatic piston to operate said valve, communicating with the air-compressing cylinder on one side and with the air-discharge pipe on the other side, a chamber between said eduction-valve and said air-discharge pipe, and a balancing-ring in said chamber, at the rear of said valve and moving therewith, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THEODORE H. SMITH.

Witnesses:

N. E. W. SMITH, ELMER WICKES. 

